Message Transmission Method and Apparatus, UE, and Storage Medium

Abstract

A message transmission method includes sending, by first UE, a first message to second UE by using a single carrier, where the first message is a message of an SL signaling radio bearer.

What is claimed is: 
     
         1 . A message transmission method, wherein the method comprises:
 sending, by first user equipment (UE), a first message to second UE by using a single carrier, wherein   the first message is a message of a sidelink (SL) signaling radio bearer.   
     
     
         2 . The method according to  claim 1 , wherein the message of the SL signaling radio bearer comprises at least one of the following:
 a message in an SL unicast connection establishment process;   a message in a sidelink radio resource control (SL RRC) reconfiguration process; or   a message in an SL discovery process.   
     
     
         3 . The method according to  claim 1 , wherein the single carrier is determined based on one of the following:
 a first SL carrier configuration in at least one SL carrier configuration, wherein the at least one SL carrier configuration is configured or preconfigured by a network-side device; and   a default SL carrier configuration, wherein the default SL carrier configuration is configured or preconfigured by the network-side device.   
     
     
         4 . The method according to  claim 1 , wherein the first message comprises a first target message, and the first target message comprises at least one of the following:
 a unicast connection establishment request message;   a security mode command complete message;   an SL UE assistance message, wherein the SL UE assistance message comprises preferred carrier configuration information;   an SL UE capability request message;   an SL UE capability response message; or   an SL RRC reconfiguration message.   
     
     
         5 . The method according to  claim 4 , wherein the first message is the SL RRC reconfiguration message, and the SL RRC reconfiguration message comprises carrier configuration information; and
 after the sending, by first UE, a first message to second UE by using a single carrier, the method further comprises:   in a case that a first condition is met, performing, by the first UE, at least one of the following:   sending a second message to the second UE by using at least two carriers, wherein the second message is a message of the SL signaling radio bearer; or   performing unicast service transmission with the second UE by using at least two carriers.   
     
     
         6 . The method according to  claim 4 , wherein the first message is the SL RRC reconfiguration message, and the SL RRC reconfiguration message comprises carrier configuration information; and
 after the sending, by first UE, a first message to second UE by using a single carrier, the method further comprises:   in a case that a second condition is met, performing, by the first UE, at least one of the following:   keeping sending a second message to the second UE by using the single carrier, wherein the second message is a message of the SL signaling radio bearer;   maintaining unicast service transmission with the second UE by using the single carrier; or   re-initiating an SL RRC reconfiguration process until a first condition is met.   
     
     
         7 . The method according to  claim 5 , wherein
 the first condition comprises at least one of the following:   the carrier configuration information comprises N lists of SL carrier configurations, and the first UE receives an SL RRC reconfiguration complete message from the second UE, wherein N is an integer greater than 1; or   the first UE receives an SL RRC reconfiguration complete message from the second UE, wherein the SL RRC reconfiguration complete message comprises M lists of SL carrier configurations, wherein M is a positive integer greater than 1.   
     
     
         8 . The method according to  claim 5 , wherein a carrier configuration indicated by the carrier configuration information is an initial configuration. 
     
     
         9 . The method according to  claim 6 , wherein
 the second condition comprises at least one of the following:   the carrier configuration information comprises one SL carrier configuration, and the first UE receives an SL RRC reconfiguration complete message from the second UE;   the first UE receives an SL RRC reconfiguration complete message from the second UE, wherein the SL RRC reconfiguration complete message comprises one SL carrier configuration;   the first UE receives an SL RRC reconfiguration failure message from the second UE;   a unicast connection establishment process between the first UE and the second UE fails; or   the SL RRC reconfiguration process of the first UE fails.   
     
     
         10 . A message transmission method, wherein the method comprises:
 receiving, by second UE, a first message sent by first UE by using a first carrier; and   sending, by the second UE, a third message to the first UE by using a second carrier, wherein   either of the first carrier and the second carrier is a single carrier, and the first message and the third message are both messages of an SL signaling radio bearer.   
     
     
         11 . The method according to  claim 10 , wherein the message of the SL signaling radio bearer comprises at least one of the following:
 a message in an SL unicast connection establishment process;   a message in an SL RRC reconfiguration process; or   a message in an SL discovery process.   
     
     
         12 . The method according to  claim 10 , wherein the first carrier and/or the second carrier are/is determined based on one of the following:
 a first SL carrier configuration in at least one SL carrier configuration, wherein the at least one SL carrier configuration is configured or preconfigured by a network-side device; and   a default SL carrier configuration, wherein the default SL carrier configuration is configured or preconfigured by the network-side device.   
     
     
         13 . The method according to  claim 10 , wherein the third message comprises a second target message, and the second target message comprises at least one of the following:
 a security mode command message;   a unicast connection establishment response message;   an SL UE assistance message, wherein the SL UE assistance message comprises preferred carrier configuration information;   an SL UE capability request message;   an SL UE capability response message; or   an SL RRC reconfiguration message.   
     
     
         14 . The method according to  claim 13 , wherein the third message is the SL RRC reconfiguration message, and the SL RRC reconfiguration message comprises carrier configuration information; and
 after the sending, by the second UE, a third message to the first UE by using a second carrier, the method further comprises:   in a case that a third condition is met, performing, by the second UE, at least one of the following:   sending a fourth message to the first UE by using at least two carriers, wherein the fourth message is a message of the SL signaling radio bearer; or   performing unicast service transmission with the first UE by using at least two carriers.   
     
     
         15 . The method according to  claim 13 , wherein the third message is the SL RRC reconfiguration message, and the SL RRC reconfiguration message comprises carrier configuration information; and
 after the sending, by the second UE, a third message to the first UE by using a second carrier, the method further comprises:   in a case that a fourth condition is met, performing, by the second UE, at least one of the following:   keeping sending a fourth message to the first UE by using the second carrier, wherein the fourth message is a message of the SL signaling radio bearer;   maintaining unicast service transmission with the first UE by using the second carrier; or   re-initiating an SL RRC reconfiguration process until a third condition is met.   
     
     
         16 . The method according to  claim 14 , wherein
 the third condition comprises at least one of the following:   the carrier configuration information comprises L SL carrier configurations, and the second UE receives an SL RRC reconfiguration complete message from the first UE, wherein L is an integer greater than 1; or   the second UE receives an SL RRC reconfiguration complete message from the first UE, wherein the SL RRC reconfiguration complete message comprises K SL carrier configurations, wherein K is a positive integer greater than 1.   
     
     
         17 . The method according to  claim 14 , wherein a carrier configuration indicated by the carrier configuration information is an initial configuration. 
     
     
         18 . The method according to  claim 15 , wherein
 the fourth condition comprises at least one of the following:   the carrier configuration information comprises one SL carrier configuration, and the second UE receives an SL RRC reconfiguration complete message from the first UE;   the second UE receives an SL RRC reconfiguration complete message from the first UE, wherein the SL RRC reconfiguration complete message comprises one SL carrier configuration;   the second UE receives an SL RRC reconfiguration failure message from the first UE;   a unicast connection establishment process between the second UE and the first UE fails; or the SL RRC reconfiguration process of the second UE fails.   
     
     
         19 . A UE, comprising a processor and a memory, wherein the memory stores a program or instructions capable of running on the processor, and the program or instructions, when executed by the processor, causes the UE to perform:
 sending a first message to second UE by using a single carrier, wherein   the first message is a message of an SL signaling radio bearer.   
     
     
         20 . A UE, comprising a processor and a memory, wherein the memory stores a program or instructions capable of running on the processor, and when the program or instructions are executed by the processor, the steps of the message transmission method according to  claim 10  are implemented.